Method and system for storing, retrieving, and managing data for tags

ABSTRACT

This invention relates generally to a method and system for storing, retrieving, and managing data for tags that are associated in some manner to any type of object. More particularly, the present invention writes data to these tags, reads data from these tags, and manages data that is written to and/or read from these tags. In addition, the invention accesses and/or stores data associated with tags from or into repositories, constructs and maintains data structures from these repositories and responds to queries using the data structures.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. patent application Ser. No.14/609,470, filed Jan. 30, 2015, U.S. Pat. No. 9,218,520, which is acontinuation of U.S. patent application Ser. No. 13/668,571, filed Nov.5, 2012, now U.S. Pat. No. 8,952,814, which is a continuation of U.S.patent application Ser. No. 13/114,139, filed May 24, 2011, now U.S.Pat. No. 8,314,705, which is a continuation of U.S. patent applicationSer. No. 11/657,895, filed Jan. 24, 2007, now U.S. Pat. No. 7,956,742,which is a continuation-in-part of U.S. patent application Ser. No.10/952,789, filed Sep. 30, 2004, now U.S. Pat. No. 7,388,488, whichclaims priority from U.S. Provisional Patent Application Ser. No.60/515,449, filed Oct. 30, 2003, the contents of all of which isincorporated herein by reference.

FIELD OF THE INVENTION

This invention relates generally to a method and system for storing,retrieving, and managing data for tags that are associated in somemanner to any type of object. More particularly, the present inventionwrites data to these tags, reads data from these tags, and manages datathat is written to and/or read from these tags.

In addition, the invention stores and/or accesses data associated withtags into or from repositories, constructs and maintains data structuresfrom these repositories and responds to queries using the datastructures.

BACKGROUND OF THE INVENTION

This invention involves a method and system for storing, retrieving, andmanaging data for any type of tag that is associated in any type ofmanner to any type of object, physical or abstract, animate orinanimate. A tag is any device that sends, receives and/or stores dataabout whatever it is monitoring or is associated with; it includes manydifferent types such as radio frequency identification device (RFID)tags, laser tags, cellular phones, devices that receive and transmitsignals from television networks, any type of satellite communicationnetwork such as a Global Positioning System (GPS), etc. A tag may bepowered by any type of power source such as a DC power source, an ACpower source, solar, etc. Identification devices are further describedin U.S. Pat. No. 3,752,960 to Charles Walton, entitled, “ElectronicIdentification & Recognition System,” the contents of which are hereinincorporated by reference. The types of objects that may be associatedwith tags include but are not limited to people, animals, plants, thingsof any kind, real property such as houses, lots, condominiums, mobilehomes and townhouses, valuable items such as paintings, diamonds,jewelry, watches, and antiques, movable items such as automobiles,airplanes, military vehicles, bicycles, motorcycles, boats, ships,components thereof, locations, environmental conditions, abstractions,concepts, phenomena, etc. Associations between tags and objects can beof any type including but not limited to one-to-many, many-to-one orone-to-one, physical, logical, etc. Physical associations may includeattaching and/or inserting the tag to its associated object.

The present invention is adapted for a wide variety of uses. Forexample, the method and system of the present invention may be used toauthenticate valuable items, to manage inventory such as the tracking ofobjects of any kind through manufacturing, supply chain, distribution,etc. to the point of sale and beyond, to track the movements of objectssuch as people, animals, plants, movable items, etc., to retrievehistorical data such as price histories from things such as valuableitems and real property, to retrieve any type of health data such asmedical conditions, treatment history, medication instructions, etc.from people and animals, to track any type of health conditions such asheart rate, pulse rate, temperature, the amount of different things inthe blood such as oxygen, sugar, etc. for people and animals.

The present invention may also be used to learn who owns a certainentity, where an entity is located, when a movable entity was lastwithin a spatial vicinity, what entities were within a spatial vicinityof a specific entity, E [either during a specified temporal period orover E's entire recorded lifetime], what entities had a particularattribute value (e.g., temperature) when they were in a spatial vicinityof any entity that had a particular attribute value during the time itwas within the spatial vicinity, etc. Exemplary queries include thefollowing:

“What are the addresses and purchase prices of the houses in StonyBrook, N.Y. that have the same brand of water heater as the water heaterin the house at 1234 Belvedere Road, Stony Brook, N.Y.?”

“What are the current traffic conditions of U.S. Highway 101 in the cityof Santa Barbara?”

“What were the traffic conditions of U.S. Highway 101 in the city ofSanta Barbara on 2005 Oct. 12 between 10:00 and 10:12?”

“Give me the current location of food items that originated in Bangkok,Thailand that, after last Saturday, were within 1 mile of chemicalcompounds which, at any time, passed through San Pedro harbor.”

“Give me the name of the doctor of every person who was in Peking at thesame time as any food item was in Peking, which was in Bangkok, Thailandafter person X was diagnosed with Avian Flu.”

“Give me the location of every product produced in any manufacturingfacility on any day that any member of group X was present at thatmanufacturing facility.”

“Give me the name of the doctor of every person whose homocysteine levelincreases by more than 15% within 12 months of purchasing a prescriptiondrug that contains lycopene manufactured in Belgium.”

The first three queries could be asked by a passenger in a car, or by acar on behalf of its driver. The benefits are similar to thoseattributed to traffic reports on radio stations.

Many different benefits may arise from the various uses of the presentinvention. For example, its use may decrease the costs of determiningthe value of a thing such as a valuable item because, for instance, theprice history and other similar data for that item could be easilystored and retrieved from its associated tag. The availability of pricehistory from a tag associated with a house as well as that from otherhouses in the same neighborhood may prevent a seller from charging anexcessively high value to a buyer with little or no knowledge of theactual value of the house. Use of the present invention may prevent thefraudulent substitution of a counterfeit for a valuable item becauseidentification data from the item's associated tag could be used toverify that item's authenticity. Use of the present invention mayprevent a car owner from passing off a damaged car as an undamaged oneto an unsuspecting buyer because a car's accident history could bestored and retrieved from the car's associated tag. Use of the presentinvention could prevent the theft of military secrets because clearanceinformation could be easily accessed from the tag associated with aperson to determine whether that person should have access to suchsecrets. Use of the present invention may avoid injury or even death toathletes that may occur while they are performing because their heartrate, temperature, and other medical conditions could be easilymonitored. For similar reasons, a coach could use the present inventionto quickly determine which players are too fatigued to be effective; anathletic recruiter could use the present invention to determine whichplayers are better able to handle the rigors of competition; andathletic trainers could use the present invention to tailor trainingprograms to particular athletes. Use of the present invention may easethe authentication of evidence at trial because chain of custody couldbe easily retrieved from the evidence's associated tag at trial. Use ofthe present invention will further automate and simplify the managementof inventory.

The present invention may also facilitate the timely location of taintedfood, or people who have been exposed to a virus. It may associate agroup of people with an event through a long chain of prior conditionsor events. It may be used to predict the popularity of an item (e.g., asong, stock, book, or vacation resort) by examining high orderderivatives with respect to time of purchase patterns in areas or setsof people that are deemed to be trend setters. It can, for example, beused to determine if any congressman was in contact with (e.g.,communicated via the telephone with, or was in the same room as) someonewhose car or cellular phone, in a 48-hour period (before and after thatpoint in time), was within ¼ mile of the Chinese Embassy. Monitoringcomplex events (e.g., flu outbreaks, and bioterrorism as manifested viaEmergency Room data) can be formulated as standing queries, obviatingthe expenses associated with a special-purpose system for suchmonitoring.

Tags and similar devices have been disclosed in other references but noprior art reference discloses the use of such tags in a system andmethod for storing, retrieving and managing data for a variety ofapplications including authentication, tracking, health care monitoring,health care management, knowledge acquisition, etc. In contrast, forexample, U.S. Pat. Nos. 6,440,096, 5,358,514, 5,193,540, 6,107,102, and6,405,066 discuss the implantation of microdevices in people. U.S. Pat.Nos. 5,606,260, 4,892,709, 5,367,878, 6,152,181, 5,834,790, 5,186,001,5,839,056, and 5,144,298 discuss the use of microdevices as sensors orcontrollers.

Accordingly, there exists a need for a system and method for storing,retrieving, and managing data for any type of tag that is associated inany type of manner to any type of object.

Moreover, there exists a need for a system and method for accessingand/or storing data associated with tags from or into many repositories,constructing and maintaining data structures from these repositories,and responding to queries using data structures.

SUMMARY OF THE INVENTION

The invention provides a system and method for storing, retrieving, andmanaging data for any type of tag that is associated in any type ofmanner to any type of object for a variety of applications.

In particular, it is an aspect of the present invention to present asystem for storing, retrieving and managing data for one or more objectscomprising:

one or more tags associated with the one or more objects;

one or more components communicating with at least one of the tags;

at least one receiver for receiving control data and information datafrom at least one of said components into at least one of said tagswherein said information data is about the object that is associatedwith said at least one tag;

at least one transmitter for transmitting at least a portion of saidinformation data to at least one of said components in accordance withsaid control data; and

at least one communication network for facilitating said communicatingamong said components and said tags;

wherein at least one of said components transmits at least one query toreceive at least a portion of said information data about said objectassociated with said at least one tag.

It is a further aspect of the present invention to present a method forstoring, retrieving, and managing data for one or more objectscomprising the steps of:

associating one or more tags with the one or more objects;

communicating with at least one of said tags from one or morecomponents;

receiving control data and information data from at least one of saidcomponents into at least one of said tags wherein said information datais about the object that is associated with said at least one tag;

transmitting at least a portion of said information data from said at,least one tag to at least one of said components in accordance with saidcontrol data; and

transmitting from said at least one of said components at least onequery to receive at least a portion of said information data about saidobject associated with said at least one tag.

It is a further aspect of the present invention to present a method formanaging children comprising the steps of:

associating one or more tags with the one or more children;

transmitting control data and information data to said one or more tags;

receiving said information data into said one or more tags, saidinformation data concerning one or more of the following: the identityof people that came into contact with the one or more children; at leastone measurement of at least one environmental condition to which the oneor more children was exposed, the academic performance of the one ormore children, the athletic performance of the one or more children, atleast one measurement of the medical condition of the one or morechildren; and

transmitting at least a portion of said information data from said atleast one tag in accordance with said control data.

It is a further aspect of the present invention to present a method forretrieving and organizing data that is associated with one or more tagshaving one or more identifiers from a plurality of repositoriescomprising the steps of:

responding to queries and search requests;

retrieving said data from one or more of said repositories; and

linking together at least one portion of said data that is associatedwith at least one of said one or more identifiers.

It is a further aspect of the present invention to present a system forretrieving and organizing data that is associated with one or more tagshaving one or more identifiers from a plurality of repositoriescomprising:

means for responding to queries and search requests;

means for retrieving said data from one or more of said repositories;and

means for linking together at least one portion of said data that isassociated with at least one of said one or more identifiers.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other aspects and features of the invention will be moreclearly understood from the following detailed description along withthe accompanying drawing figures, wherein:

FIG. 1 is a block diagram showing the major operational elements of theinvention.

FIG. 2 is a dataflow diagram describing the storage of data to tags 102that are associated with any kind of object.

FIGS. 3a and 3b are dataflow diagrams describing the transmission ofdata from tags 102.

FIG. 4a displays a sample fill-out form 400 completed by a parent at aclient computer 106 to control the operation of the child's tag 102.

FIG. 4b displays a sample fill-out form 450 completed by a parent at aclient computer 106 to retrieve data from the child's tag 102 or from adatabase 110.

FIG. 5 is a data flow diagram 500 illustrating the operation of oneembodiment of a tag for proximity checking.

FIGS. 6a, 6b, and 6c show exemplary formats of the tag-identifierbroadcast, the central authority broadcast and the tag identifier mapbroadcast respectively.

FIG. 7 is a data flow diagram illustrating the operation of oneembodiment of a tag for an out-of-proximity alarm.

FIGS. 8a, 8b, and 8c show exemplary formats of the tag-identifierbroadcast, the control authority enable and the control authoritydisable respectively.

FIG. 9 is a data flow diagram illustrating the operation of oneembodiment of a tag for a symmetric proximity alarm.

FIGS. 10a, 10b, and 10c show exemplary formats of the tag-identifierbroadcast, the control authority add tag broadcast and the controlauthority delete tag broadcast respectively.

FIG. 11 illustrates an association between a tag and its associatedentity's associated data.

FIG. 12 shows an exemplary abbreviated PML file.

FIG. 13 illustrates some exemplary data sources that may be associatedindirectly with tag data.

FIG. 14 is a block diagram showing the main operational elements of oneembodiment of the invention.

FIG. 15 is a schematic of the Crawling Subsystem of one embodiment ofthe invention.

FIG. 16 shows, in block (A), an exemplary hierarchical tag data filefrom a manufacturer. FIG. 16 also shows, in block (B), an exemplaryhierarchical tag data file from a distributor. FIG. 16 further shows, inblock (C), the identification of hierarchies in blocks (A) and (B),based on the tag identifier value.

FIG. 17 shows a 2-dimensional taxonomy of some exemplary embodiments ofthe invention: number of tag data repositories vs. number of authorizedusers.

FIG. 18 shows an example of data may be associated with tags as well asentities, and the tags and entities are themselves associated with eachother.

DETAILED DESCRIPTION

The invention provides a system and method for storing, retrieving, andmanaging data for any type of tag that is associated in any type ofmanner to any type of object (physical or abstract, animate orinanimate) for a variety of applications.

While the present invention will be explained within the context ofseveral different applications such as the authentication of objectsincluding valuable items and evidence, and the monitoring of children bytheir parents, the present invention can be applied to any applicationwhich would benefit from the storage, retrieval and management of datafor tags that are associated with any kind of object. These applicationsinclude the exchange of objects such as real property, goods, andservice, monitoring the vital signs of the ill, the elderly andathletes, athletic training programs, monitoring environmentalconditions, traffic, and consumer behavior in various settings such asamusement parks, shopping centers, casinos, tracking the location ofpeople such as prisoners, students, foreigners, military personnel, andworkers in classified areas, tracking the location of goods of any typesuch as inventory from manufacturing, the supply chain, distribution,etc. to the point of sale and beyond, tracking the location ofclassified material, tracking the manufacturing, sale and repairhistories of goods such as machinery, cars, airplanes, trains, andcomponents thereof, monitoring movement of people and things such asvehicles, traffic, etc. at locations such as a battlefield, a highway,etc., monitoring the flow of oil and other fluids in pipelines, etc.

FIG. 1 is a block diagram 100 showing the major operational elements ofthe invention. The invention may include one or more tags 102 that maybe associated with objects of any type including people, animals,plants, things of any kind, real property such as houses, lots,condominiums, mobile homes and townhouses, valuable items such aspaintings, diamonds, jewelry, watches, and antiques, vehicles such asautomobiles, airplanes, military vehicles, bicycles, motorcycles, boats,ships, components, locations, environmental conditions, abstractions,concepts, phenomena, etc. Associations between tags and objects can beof any type including one-to-many, many-to-one or one-to-one. Theseassociations may be physical, logical, etc. Physical associations mayinclude attaching and/or inserting the tag to or in its associatedobject. Logical associations may include information in a database suchas a table that may establish a correspondence between one or more tagsand one or more objects by their identification numbers.

The tags 102 may be one of a variety of a different types includingRadio Frequency Identification Device (RFID) tags, laser tags, cellularphones, devices that receive and transmit signals from a GlobalPositioning System (GPS), etc. The tags 102 may be powered by any kindof power source such as a DC power source, an AC power source, solarpower, etc. Each tag 102 may have the ability to receive data, storedata, sense data and/or transmit data. Data may be received andtransmitted to other tags 102, sensors 104, computers 106, and databasemanagement systems 110. The tags 102 may have the ability to sense datafrom its associated object, its environment, etc. Data sensed from anassociated object such as a person or animal may include medical datasuch as temperature, oxygen content in the blood, heart rate, etc. Datasensed from the environment may include the content of various gases,poisons, and pollutants in the air or water, the temperature, thehumidity, barometric pressure, chemicals, motion, light, sound, etc.

The present invention 100 may further include sensors 104. Sensors 104may be of any type and may sense any kind of data. Sensors 104 may bepowered by any type of power source such as an AC power source, a DCpower source, solar power, etc. Sensors 104 may include thermometers,motion detectors, Global Positioning System (GPS) devices, chemicalsensors, etc. Computers 106 may include database management systems 110for the storage and management of data associated with tags 102 in anyway including data transmitted to and/or retrieved from the tags 102.Data may be transmitted to tags 102 from computers 106 for storagewithin the tags 102 and may be transmitted from the tags 102 tocomputers 106. Data retrieved from tags 102 may be stored and managed indatabase management system 110.

The present invention may further include a communication network 114,which may include a variety of different types of components andsoftware to communicate different types of data among the tags 102,sensors 104, computers 106, etc. These components and software mayinclude modulator/demodulators (modems), satellites, up and downfrequency converters including those for communications with thesatellites, audio/video encoders, routers, hubs, bridges, etc. In oneembodiment, the communication network 114 may be a cellular telephonenetwork. In another embodiment, the communication network 114 may be anytype of satellite network such as GPS. In another embodiment, thecommunication network may be a television network. In anotherembodiment, the communication network 114 may include the Internet.Communication may be accomplished on the Internet by one or moreinternet applications, including the World Wide Web. Communicationnetwork 114 may be an intranet or an extranet. An intranet is a privatenetwork typically a local area network (LAN) or a wide area network(WAN) that enables the use of Internet-based applications in a secure,private environment. Extranets are intranet-type networks that linkmultiple sites or organizations using intranet related technologies.

The World Wide Web is built on a protocol called the Hypertext TransportProtocol (HTTP). Computers 106 may include browser software 108 forrequesting data input by tags 104 and sensors 102, and/or data stored ina database management system 110. Requests for data from browsersoftware 108 may be handled by server software 109. The server software109 may locate the requested data and may transmit it to the requestingbrowser software 108. Computers 106 may further include applicationserver software 111, which may extend the capabilities of the serversoftware 109. In particular, the application server software 111 maypre-process a page of data before it is sent to the requesting browsersoftware 108.

In one embodiment, the application server software 111 is a Cold Fusionapplication. Cold Fusion is a World Wide Web application for creatingdynamic page applications and interactive Web sites by combiningstandard Hypertext Markup Language (HTML) files with Cold Fusion MarkupLanguage (CFML) instructions, as specified in “The Macromedia ColdFusion 5 Web Application Construction Kit,” Ben Forta and Nate Weiss,Fourth Edition, (hereinafter, “Cold Fusion 5”), Chapter 1, the contentsof which are herein incorporated by reference. HTML is a page markuplanguage that enables the creation and layout of pages and forms. In oneembodiment of the present invention, a Cold Fusion application definesfill-out forms for entry of data including the data to control theoperation of the tags 102 and sensors 104 and queries for data.

In one embodiment, a Cold Fusion application 111 is used to retrieve orupdate data in the database management system 110. The Cold Fusionapplication 111 may access the database management system 110 through aninterface called Open Database Connectivity (ODBC), which is a standardApplication Programming Interface (API) for accessing information fromdifferent database systems and different formats, as explained inColdFusion 5, Chapter 6, the contents of which are herein incorporatedby reference.

In an alternate embodiment, data may be input using a program written ina language that manipulates text, files and information. An exemplarylanguage is PERL as specified in “Programming Perl,” Larry Ward andRandal L. Schwartz, O'Reilly & Associates, Inc., March 1992, thecontents of which are herein incorporated by reference.

The database 110 may be a distributed database, which may be storedamong many computers 106 or may be a central database. Database 110 maybe of any type including a relational database or a hierarchicaldatabase. Databases and database management systems are described inDatabase System Concepts, Henry F. Korth, Abraham Silberschatz,McGraw-Hill 1986, Chapter 1, the contents of which are hereinincorporated by reference. Exemplary databases 110 include: MicrosoftStructured Query Language (SQL) Server, Microsoft Access 1.0, 2.0 and7.0, Microsoft FoxPro 2.0, 2.5 and 2.6, Oracle 7.0, Borland Paradox 3.Xand 4.X, Borland dBase III and dBase IV, and Microsoft Excel 3.0, 4.0and 5.0.

In one embodiment, data is retrieved, inserted, updated or deleted fromdatabase 110 using Structured Query Language (SQL). SQL is described in“SAMS Teach Yourself SQL,” 2^(nd) Edition, Ben Forta, the contents ofwhich are herein incorporated by reference.

The present invention may include additional components to manage thedata received from tags 102, sensors 104 and elsewhere. These additionalcomponents may include a search tool. In one embodiment, the search toolis Verity. Data may be organized into one or more collections. Veritymay then be used to index the collection and compile metadata about thecollection to enable it to search the collection quickly. Conceptually,Verity's usefulness is attributed to its ability to index and compileinformation about the collection and use this information to quicklysearch the collection when asked to do so. Searches and queries may bespecified using Verity operators including concept operators such asSTEM, WORD, and WILDCARD, proximity operators such as NEAR and PHRASE,relation operators such as CONTAINS, MATCHES, STARTS, ENDS andSUBSTRING, search modifiers such as CASE, MANY, NOT, and ORDER and scoreoperators such as YES, NO, COMPLEMENT, PRODUCT, and SUM. Search formsand search results pages may be defined using HTML with Cold Fusiontags. The creation and searching of collections, and the display ofsearch results using Verity is described in ColdFusion 5, Chapter 36,the contents of which are herein incorporated by reference. Web Browsersoftware 108 may display the web pages from the server software 109including the fill-out form for data input, the fill-out form for inputof search criteria and the search results text data. The presentinvention may also display audio and video data input by tags 102 andsensors 104 using an on-demand video and audio streaming server, such asRealServer as explained in “RealServer Administration and ContentCreation Guide”, the contents of which are herein incorporated byreference.

In another embodiment, the search engine may be a commercial searchengine such as Alta Vista, Google, Yahoo, etc. A commercial searchengine may be integrated into the present invention using Cold Fusiontags as explained in ColdFusion 5, Chapter 36.

Before performing the search, the search engine may optimize the queriesas specified in Database System Concepts, Henry F. Korth, AbrahamSilberschatz, McGraw-Hill 1986, Chapter 9, the contents of which areherein incorporated by reference.

FIG. 2 is a dataflow diagram 200 describing the storage of data to tags102 that are associated with any kind of object. A dataflow diagram is agraph whose nodes are processes and whose arcs are dataflows. See ObjectOriented Modeling and Design, Rumbaugh, J., Prentice Hall, Inc. (1991),Chapter 1, the contents of which are herein incorporated by reference.The data may consist of control data that governs the operation of thetag 102 such as by defining what types of data the tag 102 is authorizedto receive and/or transmit, the identification of those components(i.e., other tags 102, computers 106, browser software 108, serversoftware 109, sensors 104, etc.) that may transmit data to or receivedata from the tag 102, and may consists of information for storagewithin the tag 102. In step 202, the tag 102 may await the receipt ofdata. Control proceeds to step 204 when data is received. In step 204,the tag 102 may receive data, which may have been transmitted from anytype of component including but not limited to a computer 106, browsersoftware 108, server software 109, a database 110, a sensor 104, anothertag 102, itself, etc. In step 206, a check may be done to determinewhether or not the received data is authorized to be stored in the tag102. Step 206 may include checking whether the source of the data hasthe authority to store the type of data that was received at the tag102.

The checking may be performed by a variety of different techniquesincluding but not limited to those using cryptography, the art andscience of keeping messages secure, and any other type of securecommunication including an intranet, a virtual private network (VPN),etc. Cryptography may be used in the present invention forauthentication, integrity and/or non-repudiation. Authentication enablesa receiver of a message to ascertain its origin. Integrity enables areceiver of a message to verify that the message has not been modifiedin transit. Non-repudiation prevents a sender of a message from falselydenying that it did indeed send the message.

In one embodiment, a symmetric algorithm is used. With symmetricalgorithms, the encryption key can be calculated from the decryption keyand vice versa. The key must remain secret to keep the communicationsecret. In another embodiment, a public key algorithm (also calledasymmetric algorithm) is used. With a public key algorithm, thedecryption key cannot be computed from the encryption key in areasonable amount of time. The encryption key is made public and iscalled the public key. The decryption key is kept secret and is calledthe private key. In another embodiment, digital signatures may be used.With digital signatures, a message is encrypted with a private key by asender, thereby signing the message and decrypted with a public key bythe recipient, thereby verifying the signature. Exemplary digitalsignature algorithms include Rivest-Shamir-Adelman (RSA) and the DigitalSignature Algorithm (DSA) proposed by the National Institute ofStandards and Technology (NIST). Cryptography, including symmetricalgorithms, public-key algorithms and digital signatures are describedin “Applied Cryptography” by Bruce Schneier, Chapters 1, 2, 19 and 20,the contents of which are herein incorporated by reference.

In another embodiment, the checking may be done by some form of passwordverification.

If the check in step 206 indicates that the received data is authorizedto be stored in the tag 102, then control proceeds to step 208. In step208, the data is stored in the tag 102. After step 208, control proceedsto step 202, where the tag 102 waits for the receipt of new data. If thecheck in step 206 indicates that the received data is not authorized tobe stored in the tag 102, then control returns to step 202.

FIGS. 3a and 3b are dataflow diagrams describing the transmission ofdata from tags 102. In step 302, a check is performed to determinewhether the tag 102 should be transmitting data without solicitation andif so, what type of data it should be transmitting. This may be done bychecking control settings within the tag 102. If the check in step 302indicates that the tag 102 should be transmitting data, control proceedsto step 304. In step 304, a check is performed to determine whether thedata should be transmitted at that time. This check can be done bycomparing a clock in the tag 102 to a predetermined time setting. If thecheck in step 304 indicates that data should be transmitted, thencontrol proceeds to step 308. Otherwise, control remains in step 304. Instep 308, the data is transmitted from the tag 102. After step 308,control returns to step 302.

In step 310, the tag 102 awaits a request for data. Control remains instep 310 until such a request is received after which it proceeds tostep 312. In step 312, the tag 102 may receive the request, which mayhave been transmitted from any type of component including but notlimited to a client 106, a server 108, a database 110, a sensor 104,another tag 102, etc. In step 312, a check may be done to determinewhether or not the received request is authorized to receive a responsein the tag 102. Step 312 may include checking whether the source of therequest has the authority to receive the type of data that is requested.The checking may be performed by a variety of different techniquesincluding those using cryptography, as explained in detail above. Thechecking may alternatively be done by some form of passwordverification. If the check in step 312 indicates that the request isauthorized to receive data in response, then control proceeds to step314. In step 314, the requested data is transmitted to the source of therequest. After step 314, control proceeds to step 310, where the tag 102waits for the receipt of a new request. If the check in step 312indicates that the request is not authorized to receive data inresponse, then control returns to step 310.

In one embodiment, communication between one or more of the tags 102 andone or more of the sensors 104 with the server software 109 may beperformed using a Wireless Application Protocol (WAP), which isdescribed in ColdFusion 5, Chapter 34, the contents of which areincorporated by reference.

The present invention may have many different uses. For example, itcould be used by parents to monitor their children's activities. Aparent may associate a tag 102 to a child by any means such as byphysically attaching or implanting the tag 102 on the child. Frombrowser software 108 or elsewhere, a parent may transmit control data tothe child's tag 102 to indicate that the tag 102 should accept data fromother tags 102 associated with particular people, sensors 104 such asglobal positioning system (GPS) satellites identifying the child'slocation throughout the day or environmental sensors 104 identifying thecontent of the air or water (i.e., toxins) to which the child isexposed. The tag 102 on the child executes the process for the storageof data in tags 102 illustrated by the flow diagram of FIG. 2 in orderto analyze and store the control information sent by the parent. At asubsequent time, the parent may transmit one or more queries frombrowser software 108 or elsewhere to learn the identity of the peoplethat came into contact with the child, to retrieve test scores or notesfrom a teacher that the child may have received that day, the quality ofthe air and water to which the child was exposed and the child'smovements. The tag 102 associated with the child executes the processfor transmitting data from the child's tag 102 illustrated by the flowdiagrams of FIGS. 3a and 3b in order to respond to the parent's query.

The parent may, in the alternative, transmit additional control data tothe child's tag 102 from browser software 108 or elsewhere instructingthe child's tag to periodically transmit data from the tag 102 to adatabase 110. At any subsequent time, the parent may transmit one ormore queries from browser software 108 or elsewhere to a database 110 tolearn the same information about the child.

FIG. 4a displays a sample fill-out form 400 completed by a parent atbrowser software 108 or elsewhere to control the operation of thechild's tag 102. The fill-out form may contain one or more of thefollowing fields:

Authorized Components For Receipt Table 402: This field specifies thecomponents (i.e., tags, sensors, etc.) from which the child's tag mayreceive data.

Authorized Data For Receipt Table 404: This field specifies the types ofdata (i.e., data identifying the people associated with the tags 102with which the child came into contact, test scores, teacher notes,environmental data, location data, etc.) that the child's tag 102 mayreceive.

Authorized Components For Transmission Table 406: This field specifiesthe components (i.e., database 110, etc.) to which the child's tag maytransmit data.

Authorized Data For Transmission 408: This field specifies the types ofdata that the child's tag 102 may transmit.

FIG. 4b displays a sample fill-out form 450 completed by a parent atbrowser software 108 or elsewhere to retrieve data from the child's tag102 or from a database 110. The fill-out form may contain one or more ofthe following fields:

Identification Query 452: This field requests the identify of the taggedobjects such as people and animals that came into contact with thechild.

Environmental Query 454: This field requests the content of the waterand air to which the child had contact.

Performance Query 456: This field requests data on the child's behavior,academic performance, and athletic performance.

The present invention may be used to authenticate objects such asvaluable items, sports memorabilia, and evidence. A vendor may associatea tag 102 to a valuable item such as a diamond or painting by any meanssuch as by physically attaching or implanting the tag 102 on the item.From browser software 108 or elsewhere, a vendor may transmit controldata to the object's tag 102 to indicate that the tag 102 should acceptdata from other tags 102 identifying the people associated with theother tags 102, sensors 104 such as global positioning system (GPS)satellites identifying the object's location throughout the day orenvironmental sensors 104 identifying the content of the air or water(i.e., toxins) to which the object is exposed. The tag 102 on the objectexecutes the process for the storage of data in tags 102 illustrated bythe flow diagram of FIG. 2 in order to analyze and store the controlinformation sent by the vendor. At a subsequent time, the vendor cantransmit one or more queries from browser software 108 or elsewhere tolearn the identity of the people that handled the object, the quality ofthe air and water to which the object was exposed, the object'smovements, the chain of title, the chain of possession, and the identityof the object's manufacturers, retailers, and distributors. The tag 102associated with the object executes the process for transmitting datafrom the object's tag 102 illustrated by the flow diagrams of FIGS. 3aand 3b in order to respond to the vendor's query.

The vendor may, in the alternative, transmit additional control data tothe object's tag 102 from browser software 108 or elsewhere instructingthe object's tag 102 to periodically transmit data from the tag 102 to adatabase 110. At any subsequent time, the vendor may transmit one ormore queries from browser software 108 or elsewhere to the database 110to learn information about the object.

Another embodiment of the invention performs proximity tracking. In thisembodiment, an event may be recorded within a tag when it comes within arange of other tags. These recorded events may be later sent to adatabase. This embodiment may be used generally to track the objectsthat have come into proximity with another object. For example, thisembodiment may be used to track the people that have come into contactwith a child or the places where a child has been. This embodiment mayalso be used to track the movement of objects with respect to locationswithin a secure facility.

In one embodiment, the tags may contain one or more of the following: aradio transmitter, a radio receiver, a memory, control software, aprocessor and a clock. The memory may include a RAM and a ROM. Thecontrol software may be stored in the ROM. The processor may be of atype that consumes less power.

The tags may contain one or more data structures including a tagidentifier, a tag identifier map and a time field. The tag identifiermay be a variable length string of up to 255 bytes and may be used todistinguish tags from each other. The tag identifier map may map a tagidentifier to a public key and a counter. In one embodiment, the tagidentifier map is implemented with a hash table. In another embodiment,the tag identifier is implemented with a binary search tree. The tagidentifier map may be initialized with the public keys of certain tagssuch as those that are expected to be encountered and/or those that aredetermined to be sensitive. This scheme enables tags to quickly discardmessages from tags with invalid signatures. Entries in the tagidentifier map may be discarded after the map becomes full. Entries maybe discarded in any order such as first-in-first-out (FIFO), leastrecently used (LRU), etc. The time field may be a four byte unsignedinteger and may contain the current time in any form such as GreenwichMean Time (GMT).

FIG. 5 is a data flow diagram 500 illustrating the operation of oneembodiment of a tag for proximity checking. The tag waits for aninterrupt in step 502. In step 504, the type of interrupt is determined.If the interrupt is a received interrupt, control proceeds to step 506.In step 506, the protocol identifier of the received broadcast isdetermined. The protocol identifier may be of different types such as atag-identifier broadcast, a tag identifier map broadcast, etc. Exemplaryformats of the tag-identifier broadcast, the central authority broadcastand the tag identifier map broadcast are shown in FIGS. 6a, 6b, and 6crespectively. The broadcasts may be encapsulated in a wireless broadcastpacket at the network-interface layer and multi-byte values may betransmitted in big endian order. The signatures may be RSA signatures.The signature in the tag identifier broadcast may be taken over the tagidentifier and current time fields. The signature in the centralauthority broadcast may be taken over the current time field. One ormore of the fields excluding the protocol identifier in the tagidentifier map broadcast may be encrypted with the public key of thecentral authority. The signature in the tag identifier may be taken overone or more of the fields following the current time.

If the protocol identifier is a tag identifier broadcast, controlproceeds to step 508. In step 508, the tag identifier of the tagidentifier broadcast is checked to determine if it is valid. If it isnot valid, the broadcast is ignored and control returns to step 502. Ifit is valid, control proceeds to step 510. In step 510, the time in thetag identifier broadcast is checked to determine whether it is withinone minute of the current time. If it is not, then the broadcast isignored and control returns to step 502. If it is, then control proceedsto step 512. In step 512, the tag identifier in the tag identifierbroadcast is checked to determine whether it is present in the tagidentifier map (i.e., has been previously encountered by the tag). Ifnot, control proceeds to step 514. In step 514, a new entry is createdfor the tag identifier in the tag identifier map and the number ofencounters for that entry is set to one. Control then proceeds to step502.

If the tag identifier is determined to be present in the tag identifiermap in step 512, then control proceeds to step 516. In step 516, it isdetermined whether the tag identifier in the tag identifier broadcasthas a public key. If so, then control passes to step 518. In step 518,the public key is used to verify the signature. If the signatureverification in step 518 is not successful, then the broadcast isignored and control returns to step 502. If the signature verificationin step 518 is successful, then control proceeds to step 520. In step520, the number of encounters for the tag identifier in the tagidentifier map is incremented.

If the protocol identifier is determined to be a central authoritybroadcast in step 506, then control proceeds to step 522. In step 522,the time in the central authority broadcast is checked to determine ifit is within one minute of the current time. If not, then the broadcastis ignored and control returns to step 502. If so, control proceeds tostep 524. In step 524, the public key of the central authority is usedto verify the signature in the central authority broadcast. If thesignature verification is not successful, then the broadcast is ignoredand control returns to step 502. If the signature verification in step524 is successful, then control proceeds to step 526. In step 526, thetag identifier map is encrypted with the central authority public key.In step 528, the encrypted tag identifier map is broadcast. Control thenreturns to step 502.

If the interrupt is determined to be a timer interrupt in step 504,control proceeds to step 530. In one embodiment, the timer interruptoccurs every 15 seconds. In step 530, the signature is created using thetag's private key. In step 532, the signature, the tag identifier, andthe current time are written to the tag identifier broadcast. In step534, the tag identifier broadcast is broadcast. Control then returns tostep 502.

The embodiment of FIG. 5 has a number of advantages. The signature makesit infeasible for any preregistered tag to spoof a real tag. Replayattacks are blocked by the time stamp.

The private keys may be secured; the central authority may be in asecure location; and the tags may be tamper-resistant. These optionsprevent one tag from repudiating contact with another tag. A replacementstrategy may be used to prevent attempts to flood the tag identifier mapby broadcasting of spurious tag identifiers. In another embodiment, aglobal public/private key pair may be used to authenticate broadcasts.

Another embodiment of the invention sounds an alarm within apredetermined time if a tag goes outside a particular range of one ormore other tags. In one embodiment, the range is a mutualtransmit/receive range. In one embodiment the predetermined time issixty seconds. One tag may be physically attached to a sensitive objectthat must not leave a secure area. The other tag may be built into asecure, immobile location such as a floor or ceiling or may be carriedby authorized personnel. In one embodiment, a protocol enables anddisable tags so that objections can be removed by authorized parties.

This embodiment may be used to alert security personnel to the movementof objects out of a secure facility, to alert employees to theft ofinventory from a store, to alert a parent or day-care provider to achild that strays outside of a certain area, to alert a person to thetheft of a motor vehicle, or to the theft of valuable objects from thehome, to alert a escort in a secure facility of abandonment by a guest,to alert the authorities of the escape of a criminal from prison or froma house for those criminals under house arrest, etc.

In one embodiment, the tags may contain one or more of the following: aradio transmitter, a radio receiver, a memory, control software, aprocessor, a clock and an audible alarm. The memory may include a RAMand a ROM. The control software may be stored in the ROM. The processormay be of a type that consumes less power.

The tags may contain one or more data structures including a tagidentifier, a tag identifier of a partner tag, a private key for thetag, a public key for the partner tag, a public key of a controlauthority, an alarm counter, an enable flag and a time field. The tagidentifier may be a variable length string of up to 255 bytes and may beused to distinguish tags from each other. The tag identifier of thepartner tag may be a variable length string of up to 255 bytes. Theprivate and public keys may be 16 bytes. The alarm counter may be fourbytes. The enable flag may be four bytes. The time field may be a fourbyte unsigned integer and may contain the current time in any form suchas Greenwich Mean Time (GMT).

FIG. 7 is a data flow diagram 700 illustrating the operation of oneembodiment of a tag for an out-of-proximity alarm. The tag waits for aninterrupt in step 702. In step 704, the type of interrupt is determined.If the interrupt is a received interrupt, control proceeds to step 706.In step 706, the protocol identifier of the received broadcast isdetermined. The protocol identifier may be of different types such as atag-identifier broadcast, a control-authority broadcast (including acontrol authority enable and a control authority disable), etc.Exemplary formats of the tag-identifier broadcast, the control authorityenable and the control authority disable are shown in FIGS. 8a, 8b, and8c respectively. The broadcasts may be encapsulated in a wirelessbroadcast packet at the network-interface layer and multi-byte valuesmay be transmitted in big endian order. The signature in the tagidentifier broadcast may be taken over the tag identifier and currenttime fields. The signature in the control-authority broadcast may betaken over the current time field. The signatures may be RSA signatures.

If the protocol identifier is a tag identifier broadcast, controlproceeds to step 708. In step 708, the tag identifier of the tagidentifier broadcast is checked to determine if it is valid. If it isnot valid, the broadcast is ignored and control returns to step 702. Ifit is valid, control proceeds to step 710. In step 710, the time in thetag identifier broadcast is checked to determine whether it is withinone minute of the current time. If it is not, then the broadcast isignored and control returns to step 702. If it is, then control proceedsto step 712. In step 712, the public key of a partner tag may be used toverify the signature in the tag-identifier broadcast. If the signatureverification in step 712 is not successful, then the broadcast isignored and control returns to step 702. If the signature verificationin step 712 is successful, then control proceeds to step 714. In step714, the alarm counter is reset to zero.

If the protocol identifier is determined to be a control authorityenable broadcast in step 706, then control proceeds to step 716. In step716, the time in the control authority enable broadcast is checked todetermine if it is within one minute of the current time. If not, thenthe broadcast is ignored and control returns to step 702. If so, controlproceeds to step 718. In step 718, the public key of the controlauthority is used to verify the signature in the control authorityenable broadcast. If the signature verification is not successful, thenthe broadcast is ignored and control returns to step 702. If thesignature verification in step 718 is successful, then control proceedsto step 720. In step 720, the enable flag is set to one. Control thenreturns to step 702.

If the protocol identifier is determined to be a control authoritydisable broadcast in step 706, then control proceeds to step 722. Instep 722, the time in the control authority disable broadcast is checkedto determine if it is within one minute of the current time. If not,then the broadcast is ignored and control returns to step 702. If so,control proceeds to step 724. In step 724, the public key of the controlauthority is used to verify the signature in the control authorityenable broadcast. If the signature verification is not successful, thenthe broadcast is ignored and control returns to step 702. If thesignature verification in step 724 is successful, then control proceedsto step 726. In step 726, the enable flag is set to zero. Control thenreturns to step 702.

If the interrupt is determined to be a timer interrupt in step 704,control proceeds to step 728. In one embodiment, the timer interruptoccurs every six seconds. In step 728, the enable flag is added to thealarm counter. In step 730 the alarm counter is checked to determine ifit is greater than a limit. In one embodiment, the limit may be 10seconds. If the alarm counter is greater than the limit, controlproceeds to step 732. In step 732, the tag sounds an alarm. Control thenproceeds to step 702.

If the alarm counter is determined to be less than or equal to the limitin step 730, then control proceeds to step 734. In step 734, a signatureis created using the tag's private key. In one embodiment, the signatureis taken over the tag identifier of a partner and the current time. Instep 736, the signature, the protocol identifier, the tag identifier ofa partner, and the current time are written to the tag identifierbroadcast. In step 738, the tag identifier broadcast is broadcast.Control then returns to step 702.

The embodiment of FIG. 7 has a number of advantages. The signature makesit infeasible for a phony partner tag to spoof a real tag. The signaturealso makes it infeasible for a phony control authority to disable a tag.Replay attacks are blocked by the time stamp. Destroying a tag soundsthe alarm of a partner tag.

Another embodiment of the invention sounds an alarm if a tag comeswithin a particular range of one or more other tags. Each tag maymaintain a sensitive tag list of such other tags that cause its alarm tosound. In one embodiment, the range is a mutual transmit/receive range.One tag may be physically attached to a sensitive object that must notenter a secure area. The other tag may be built into a secure, immobilelocation such as a floor or ceiling or may be carried by authorizedpersonnel. This embodiment may include a protocol for adding tags to anddeleting tags from the sensitive tag list.

This embodiment may be used to alert security personnel to the movementof objects such as dangerous or hazardous object into a sensitivefacility, to alert employees to inventory that is being carried near theexit of a store, to alert a parent or child-care provider to themovement of a child toward a dangerous area or to designated persons, towarn a pedestrian who is approaching a hazardous area, to warn amotor-vehicle driver who is approaching hazardous conditions, to alertsecurity personnel to visitors who are entering or approaching arestricted area, etc.

In one embodiment, the tags may contain one or more of the following: aradio transmitter, a radio receiver, a memory, control software, aprocessor, a clock and an audible alarm. The memory may include a RAMand a ROM. The control software may be stored in the ROM. The processormay be of a type that consumes less power.

The tags may contain one or more data structures including a tagidentifier, a private key for the tag, a public key of a controlauthority, a tag identifier map, and a time field. The tag identifiermay be a variable length string of up to 255 bytes and may be used todistinguish tags from each other. The private and public keys may be 16bytes. The tag identifier map may map a sensitive tag identifier to apublic key. The tag identifier map may be implemented by a hash table ora binary search tree. Entries in the tag identifier map may expire inleast-recently-used order if the tag identifier map becomes full. Thetime field may be a four byte unsigned integer and may contain thecurrent time in any form such as Greenwich Mean Time (GMT).

FIG. 9 is a data flow diagram 900 illustrating the operation of oneembodiment of a tag for a symmetric proximity alarm. The tag waits foran interrupt in step 902. In step 904, the type of interrupt isdetermined. If the interrupt is a received interrupt, control proceedsto step 906. In step 906, the protocol identifier of the receivedbroadcast is determined. The protocol identifier may be of differenttypes such as a tag-identifier broadcast, a control-authority add tagbroadcast, a control authority delete tag broadcast, etc. Exemplaryformats of the tag-identifier broadcast, the control authority add tagbroadcast and the control authority delete tag broadcast are shown inFIGS. 10a, 10b, and 10c respectively. The broadcasts may be encapsulatedin a wireless broadcast packet at the network-interface layer andmulti-byte values may be transmitted in big endian order. The signaturesmay be RSA signatures. The signature in the tag identifier broadcast maybe taken over the tag identifier and current time fields. The signaturein the control-authority add tag broadcast may be taken over the targettag identifier, the sensitive tag identifier, the sensitive tag publickey and the current time field. The signature in the control-authoritydelete tag broadcast may be taken over the target tag identifier, thesensitive tag identifier, and the current time field.

If the protocol identifier is a tag identifier broadcast, controlproceeds to step 908. In step 908, the tag identifier of the tagidentifier broadcast is checked to determine if it is in the tag's listof sensitive tags. If it is not in the list of sensitive tags, thebroadcast is ignored and control returns to step 902. If it is in thelist of sensitive tags, control proceeds to step 910. In step 910, thetime in the tag identifier broadcast is checked to determine whether itis within one minute of the current time. If it is not, then thebroadcast is ignored and control returns to step 902. If it is, thencontrol proceeds to step 912. In step 912, the public key of the tagidentifier in the tag identifier broadcast may be used to verify thesignature in the tag-identifier broadcast. If the signature verificationin step 912 is not successful, then the broadcast is ignored and controlreturns to step 902. If the signature verification in step 912 issuccessful, then control proceeds to step 914. In step 914, the alarmsounds.

If the protocol identifier is determined to be a control authority addtag broadcast in step 906, then control proceeds to step 916. In step916, the target tag identifier is checked to determine if it matches thetag identifier of the tag receiving the broadcast. If there is not amatch, the broadcast is ignored and control returns to step 902. Ifthere is a match, control proceeds to step 918. In step 918, the time inthe control authority add tag broadcast is checked to determine if it iswithin one minute of the current time. If it is not, then the broadcastis ignored and control returns to step 902. If it is within one minute,control proceeds to step 920. In step 920, the public key of the controlauthority is used to verify the signature in the control authority addtag broadcast. If the signature verification is not successful, then thebroadcast is ignored and control returns to step 902. If the signatureverification in step 920 is successful, then control proceeds to step922. In step 922, the sensitive tag identifier in the control authorityadd tag broadcast and its public key are stored in the tag identifiermap. Control then returns to step 902.

If the protocol identifier is determined to be a control authoritydelete tag broadcast in step 906, then control proceeds to step 924. Instep 924, the target tag identifier is checked to determine if itmatches the tag identifier of the tag receiving the broadcast. If thereis not a match, the broadcast is ignored and control returns to step902. If there is a match, control proceeds to step 926. In step 926, thetime in the control authority delete tag broadcast is checked todetermine if it is within one minute of the current time. If it is not,then the broadcast is ignored and control returns to step 902. If it iswithin one minute, control proceeds to step 928. In step 928, the publickey of the control authority is used to verify the signature in thecontrol authority delete tag broadcast. If the signature verification isnot successful, then the broadcast is ignored and control returns tostep 902. If the signature verification in step 928 is successful, thencontrol proceeds to step 930. In step 930, the sensitive tag identifierin the control authority delete tag broadcast and its public key areremoved from the tag identifier map. Control then returns to step 902.

If the interrupt is determined to be a timer interrupt in step 904,control proceeds to step 932. In one embodiment, the timer interruptoccurs every fifteen seconds. In step 932, a signature is created usingthe tag's private key. In one embodiment, the signature is taken overthe tag identifier and the current time. In step 934, the signature, theprotocol identifier, the tag identifier, and the current time arewritten to the tag identifier broadcast. In step 936, the tag identifierbroadcast is broadcast. Control then returns to step 902.

The embodiment of FIG. 9 has a number of advantages. The signature makesit infeasible for a phony sensitive tag to spoof a real tag. Thesignature also makes it infeasible for a phony control authority to addor delete a tag. Replay attacks are blocked by the time stamp. Tags maybe made to be resistant to tampering to lessen their vulnerability tophysical destruction or removal.

In another embodiment of the invention, entities may be associated withtags. Entities and tags may be associated with data. This is illustratedin FIG. 11 with Entity 1110, Data 1120 and Tag 1130. A tag may identifyits associated entity. Tags may be of different types including RFIDtags and laser tags.

The associations may be of different types such as one-to-one andmany-to-one. Associations between a tag and an entity may be physical orlogical. Exemplary physical associations include attaching the tag to orinserting the tag into, its associated entity. Examples of physicalentities that may be associated with tags may include people, animals,plants, real property such as house, lots, condominiums, mobile homesand townhomes, and valuable items such as paintings, diamonds, jewelry,watches, and antiques. Additional examples include movable items such asautomobiles, airplanes, military vehicles, bicycles, motorcycles, boatsand ships.

Examples of logical entities that may be associated with tags mayinclude parts of containers, a spatial location, a temporal location, anenvironmental condition (e.g. hurricane), an abstraction, and a concept.

Various types of data may be associated with a tagged entity. Examplesmay include common types of data (e.g., addresses, dates, invoicenumbers) and transactions (e.g., purchases, requests for quotes).

Examples of data that may be associated with a product entity includethe product's name and class (e.g., soft drink, automobile part,clothing), manufacturing date and place, expiration date, currentlocation, and current temperature. Additional examples includeinstructions for where a product may be shipped, instructions for apoint-of-sale display to lower the price as a product approaches itsexpiration date, instructions for how long a particular type ofmicrowave oven should cook a particular brand of frozen pizza, andinstructions indicating that goods be stored at a particular temperatureas they are transported.

Additional types of data that may be associated with a tagged entityinclude information that does not change such as material composition,information that changes constantly (dynamic data) and information thatchanges over time (temporal data). Dynamic data may include thetemperature of a shipment of fruit and vibration levels of a machine.Temporal data may change discretely and intermittently over the life ofan entity. Temporal data may include the location of an entity.

Data associated with tagged entities may be stored in a conventionaldatabase or a web page and may be described with a mark up language suchas the Physical Markup Language (PML). FIG. 12 illustrates an exemplary,abbreviated PML file. The PML file contains two temperature readings fora product. PML is based on extensive Markup (meta) Language (XML). PMLis described in R. Journal, The EPC global Network: FAQ: What is thePML?, Dec. 14, 2005, www.rfidjournal.com/faq/24/116, the contents ofwhich are herein incorporated by reference.

A set of primary data for a tagged entity such as a tag identifier, atime, a tag reader identifier and the GPS coordinates of the tag readermay be called a tag event. A tag event may further include sensor data(e.g., a temperature measurement) as shown by Data 1865 in FIG. 18.

Data associated with a tagged entity including tag event data and PMLdata may be accessed through a tag data repository or tag data server. Atag data repository may be any data repository (e.g., database, webserver, PML file) containing tag data. A tag data repository mayassociate each tag event with a tag identifier. Because each tagidentifier is associated with an entity and that entity may beassociated with data besides event data, such as Data 1870 in FIG. 18,the tag identifier may be associated with data besides event data. Forexample, a tag identifier may be associated with a particular car (Tags1830 and 1835, FIG. 18), and that car may be associated with a varietyof data (e.g., a manufacturing date), as illustrated by Data 1815 inFIG. 18. Thus, the car's tag identifier may be associated with the car'smanufacturing date. Physical entities may be associated with tagidentifiers of their parts. For example, a car may be associated withthe tag identifiers of its parts, as shown by the association betweenTags 1825, 1830, 1840 and 1850, and Parts (or entities) 1820, 1845 and1855 of FIG. 18. Thus, the car's tag identifier may be associated withthe tag identifiers of the car's parts, as well as Data 1810 and 1860.Since car parts may have parts of their own, a tag identifier may beassociated with a part hierarchy. In general, a tag identifier may bethe root of a tree of associated tag identifiers. Although such data maynot be tag event data, it nonetheless can be associated with a tagidentifier. A tag's associated tag identifiers may be referred to as itstag references.

The set of all tags and their tag references may be represented as adirected graph. In such a graph, the tags may be represented as nodesand the tag references may be represented as arcs. The set of tag dataincluding tag event data and other data may be referred to as theuniverse of data.

FIG. 13 presents some exemplary tag data repositories, including SensorData 1310, Database Data 1320, Web Page Data 1330, and PML Data 1340.

FIG. 14 is a block diagram showing the main components of one embodimentof the invention. The embodiment may be arranged into a crawlingsubsystem 1480, a data reorganization subsystem 1490 and a queryprocessing subsystem 1495.

The Crawling Subsystem

Crawling may involve three principle tasks, data discovery,authentication and authorization, and automatic parsing and semanticprocessing. Various participants and components in the present inventioncooperate to facilitate these tasks. Tag data procedures (e.g.,manufacturers, distributors, retailers, consumers) have the incentive tohave their data discovered in order to maximize its value. Thisincentive will grow with the continued growth of electronic commerce.

Tag data servers and TDS servers also facilitate discovery of the tagdata produced by tag data producers. A TDS server is a service thatreturns information about tag data repositories or tag data servers forwhich an entity's data may be accessed. In one embodiment, descriptionsof entity attributes (static, temporal, and dynamic) are accessedindirectly via TDS servers that are distributed within computer networkssuch as the Internet or an intranet.

In addition to facilitating the discovery of data, the tag datarepositories, tag data servers, and TDS servers may participate with acrawler in authentication and authorization. Specifically, a crawler maysubmit to authentication. If the crawler is authenticated, the crawler'sauthorization may be checked. The tag data repository, tag data serverand TDS server may then grant access to these portions of their contentsto which the crawler has authorization.

In one embodiment of the present invention, the Physical Markup Language(PML) facilitates automatic processing and semantic processing.

As shown by FIG. 14, the Crawling Subsystem 1480 may include a tag datarepository 1410, a crawler 1420, and a data space 1430. FIG. 15 is aschematic of the crawling subsystem 1480 of one embodiment of theinvention. A crawler 1420 a . . . 1420 m may access tag data eitherdirectly or indirectly for a variety of tag data repositories 1410 a . .. 1410 n. The crawler 1420 a . . . 1420 m may send the accessed data toa data space 1430 within the data reorganization system 1490. In oneembodiment, a crawling system 1480 may further include Seeder 1510 and aTask Space 1520. The Seeder 1510 may initialize the Task Space 1520 withdata acquisition tasks.

While the task space 1520 is not empty, an idle crawler 1410 a . . .1410 n will take a data acquisition task from the task space 1520,acquire the data, and put the acquired data in the result data space1430. A crawler, 1420 a . . . 1420 m, when processing a task, maydiscover additional repositories 1410 a . . . 1420 n. For example, whenthe acquired data contains a tag reference, the Crawling Subsystem 1480might hand this tag to a TDS server. For each returned tag datarepository 1410 a . . . 1410 n, a tag data server that was previouslyunknown to the Crawling Subsystem 1480, it may construct a new dataacquisition task. In general, a crawling task, in addition to producinga result for insertion into the data space 1430, may produce new dataacquisition tasks for insertion in the Task space 1520. When all thetasks that were put into the Task space 1520 have been completed (whichimplies that no new tasks will be generated), crawling is complete.

The Seeder 1510 may initialize the Task space 1520 by accessing a fileof initial data acquisition tasks and/or by systematically retrievinginformation about tag data repositories 1410 a . . . 1410 n and tag dataservers from TDS servers. The Seeder configuration file may be updatedwith the information regarding newly discovered tag data repositories1410 a . . . 1410 n, tag data servers, and TDS servers. In oneembodiment, the Task space 1520 and result space 1430 may bedistributed. The result space 1430 is the interface between the CrawlingSubsystem 1480 and the Data Reorganization Subsystem 1490.

The Data Reorganization Subsystem

As shown in FIG. 14, the Data Reorganization Subsystem 1490, may includeData Space 1430, Data Reorganizer 1440, and Reorganized Data 1450. TheData Reorganization Subsystem 1490 accesses the tag data that wasacquired for the crawling subsystem 1480 and produces data structuresthat facilitate query processing. This conversion may be illustratedusing the exemplary, abbreviated PML file of FIG. 12. In one embodiment,appropriate data structures such as relations for a relational databaseare constructed for a tag data scheme in a PML file like the oneillustrated in FIG. 12. For example, a ternary relation <tag identifier,datetime, temperature> may be updated with two rows corresponding to thetwo recorded temperature readings. Such conversions to tuples in arelational database may be referred to as shredding. An explanation ofshredding in the XML context may be found in R. Krishnamurthy, et al.,XML-to-SQL Query Translation Literature: The State of the Art and OpenProblems, XML Symposium, 2003, the contents of which are hereinincorporated by reference.

In one embodiment, the aggregation of the output of the CrawlingSubsystem 1480 (e.g., PML files and relational structures of tag data)may be done with the use of data management systems, such as DB2. DB2 iscapable of managing XML and relational data natively. In other words,each kind of data may be kept in a data structure that is inherentlysuited for that data. In the case of XML, for example, data is kept in atree-like data structure. Because the database in the embodiment managesboth XML and relational data natively, shredding is unnecessary. XMLsupport within DB2 is further explained in M. Nicola and B. van denLinden, Native XML Support in DB2 Universal Database, Proceedings of the31_(st) VCDB Conference, 2005, Trandheim, Norway, www.vldb2005.org/program/paper/thu/p1164-nicola.pdf, (hereinafter, “Native XMLSupport in DB2 Universal Database”) the contents of which are hereinincorporated by reference.

In one embodiment, the data structure may be further optimized. Forexample, relations in a relational database may be put in normal form.In addition, indices may be constructed. These and other optimizationsare described in “Native XML Support in DB2 Universal Database.” Inanother embodiment, the index may be a spatial index which spatiallyorders tag data associated with space-varying (i.e., mobile) entities. Aspatial index may facilitate, for example, the identification ofentities that were “nearly” co-located (not necessarily at the sametime). Another index may be a temporal index, which temporally orderstime-varying tag data (e.g., the temperature readings in FIG. 2). Atemporal index may allow queries to access tag data of an entity at ornear a particular time, as well as time-varying tag data associated withone entity, as a function of the time that another entity's time-varyingdata (e.g., temperature) was in a certain value interval. Another indexmay be a temporal-spatial index, which orders entity data spatiallywithin time. Such an index facilitates processing queries that requirethe determination of what entities were, for example, near entity A neartime t.

In one embodiment, the tag data associated with one entity may refer toother entities (e.g., in part-whole relations, such as what particularcarburetor is in this particular car).

In one embodiment, the invention may include a ranking algorithm.Ranking algorithms are described in D. Woolsey and M. Every's “methodand apparatus for improved relevance of search results,” (U.S. patentapplication Ser. No. 10/863,543 published on Sep. 15, 2005 as U.S.patent publication number 20050203888) the contents of which are hereinincorporated by reference. Keyword queries respond with tag data that ishighly ranked with respect to the keywords. In one embodiment, theranking algorithm may be a pluggable attribute. In one embodiment, theinvention responds to keyword queries with tag data that is highlyranked for those keywords.

In another embodiment, the result of the first step in a keyword searchmay be a set of tag identifiers. Next, tag data associated with each tagidentifier is aggregated, regardless of whether or not the source of thetag data is distributed over many data repositories (e.g., manufacturerepository, shipping repositories and a retailer repository). Thus, thepresent invention is an enhancement over a conventional web searchengine, which merely retains a list of weblinks that match a query butdoes not aggregate content from different web pages.

In one embodiment, aggregation is performed on PML structural data filesassociated with the same tag data repositories 1410 a . . . 1410 n. FIG.16 shows, in blocks (A) and (B), exemplary archival data files from amanufacturer and a distributor, respectively. The data files may includeTAG ID 1610, Manufacture Date 1620, Manufacture Location 1630, and Time,Location, Temperature 1640. FIG. 16 further shows, in block (C), theidentification of hierarchies in blocks (A) and (B) based on the tagidentifier values. To create the hierarchical data file in block (C)from the files in blocks (A) and (B), distinct trees with the same rootvalue (the same tag identifier) are combined. In other words, it issufficient to identify the roots of the distinct trees. The resultingtree is the union of the constituent tree.

In one embodiment, the crawling acts in accordance with a “push” modelof data acquisition. In another embodiment, the crawling may also act inaccordance with a “pull” acquisition model. In one embodiment, theacquisition may be triggered by event notification. Because they aremore network intensive, the acquisitions that are triggered may bereserved for the most volatile data when increased tag data timelines isrequested.

The Query Processing Subsystem

The Query Processing Subsystem 1495 may include reorganized data 1450produced by the data reorganization system 1490 and a query processor1460. In one embodiment, the query processor 1460 receives a query 1465originated by a user 1470 from a variety of sources, such as a webinterface. The query processor 1460 may use the indices and/or otherdata structures of the reorganized data 1450 to find an answer to thequery. The data processor 1460 may return the answer as a result 1475 tothe user 1470.

Tag data may not be uniformly volatile. The spectrum ranges from tagdata that is fixed for the lifetime of the associated entity (e.g.,manufacture date) to tag data that varies nearly continuously (e.g., thelocation of a highly mobile tagged entity). Responding to a user queryby real-time querying of retailers may not always be necessary orcost-effective. Less volatile data may be suited to periodic harvesting.An example is the harvesting of web pages by web search engines. Thisaspect of the invention provides an advantage over conventional queryprocessing, such as that which is done by web search engines. The mostrelevant response to a single keyword search may require knowing abouttag data from multiple repositories of different owners. For example, amanufacturer may store data associated with a particular item that ithas manufactured. A supplier also may store data associated with thatparticular item. Since both tag data files have data about the sameitem, they will have the same tag identifier, and a tag datasearch/query engine will “know” that these different tag data files areassociated with the same item. The present invention enables a tagidentifier search/query to succeed even if it requires data frommultiple original tag data source files to do so. A web search enginehas no such capability. Instead, a web page's Uniform Resource Locator(URL), the global address of documents and other resources on the WorldWide Web, uniquely defines that page. If that page is associated with aspecific entity, and another web page also is associated with thatentity, web search engines will not “know” this. Consequently, websearch engines merely focus on identifying particular web pages.

Exemplary Uses of the Invention

Exemplary uses of the present invention may be illustrated by a querysearch and a keyword search.

To learn which are the most “important (in a sense not formally defined)computer gaming graphics card in use (as opposed to what a web sitemight claim), a user might formulate the following boolean expression ofkeywords:

“Computer gaming” AND (graphics OR video) AND (card OR accelerator)

To handle this keyword search, inverted indices may be used. An invertedindex is a set of texts of the words in the texts. The index may beaccessed by a search method. Each index entry gives the word and a listof texts, possibly with locations within the text, where the wordoccurs. For web search engines, the “text” is a web page. Given a word,the inverted index returns a list of URLs whose corresponding web pagescontain that word. With the present invention, the “text” is a tag datafile. Given the word, the inverted index returns a list of tagidentifiers for which there is a tag data file containing that word.Inverted indices are further explained in Inverted Index Definition,www.nist.gov/dads/HTML/invertedIndex.html, the contents of which areherein incorporated by reference.

Let the keyword search involving n keywords be denoted by the keywordexpression.

keyword₁booleanOperator₁keyword₂booleanOperator₂ . . .booleanOperator_(n-1)keyword_(n),

where booleanOperator is either an AND or an OR operation. Eachkeyword_(i) maps to the set of tag identifiers for which there is a tagdata file containing keyword_(i). A keyword expression is associatedwith the set of tag identifiers that satisfy the boolean expression ofkeywords. In general, the expressions can be parenthesized (as is donein the illustration above). If keyword_(i) and keyword_(j) are connectedby an AND operator the resulting set of tag identifiers iskeyword_(i)∩keyword_(j); if keyword_(i) and keyword_(j) are connected byan OR operator the resulting set of tag identifiers is keyword_(i) Ukeyword_(j).

The final result set of tag identifiers may be ordered according to aranking scheme. The tag data associated with each tag identifier in thefinal result set may be presented to the user. In one embodiment of thepresent invention, the ranking scheme may vary or may be a pluggablefeature. In one embodiment, a pluggable ranking scheme is selected ateither the time of deployment or the time the search/query isformulated.

A keyword search may succeed where keyword_(i) is in tag data from onetag data repository, keyword_(j) is in tag data from another tag datarepository, and these keywords are connected by a boolean operator. Thatis, conducting the keyword search on fewer data repositories (e.g., asingle data repository) would fail. Thus, aggregating data for a singletag identifier over multiple tag data repositories significantlyenlarges the class of searches/queries to which the present inventioncan successfully respond. The tag data that is returned to the user maybe aggregated automatically over many different source tag datarepositories (e.g., manufacturing tag data repository, distributor tagdata repository, and retailer tag data repository). If a tag-rankingalgorithm is used, the response will reflect those tags that, roughlyspeaking, are most referenced among those that match the keywords. A tagdata reference from one entity to another may represent a part-wholerelationship. In particular, if a computer gaming entity has a graphicsor video card, its tag data may include the card's tag (along with thetags of the other components in its parts list, which incidentally mayhave interesting parts lists of their own, etc.). Therefore, atag-ranking algorithm would return the tag data associated with the tagsthat, roughly speaking, are referenced by the most, “important” tags.

A Query Illustration

Once a database has been constructed, users can formulate, for example,SQL queries for the database. However, XML-to-SQL translation may not benecessary because the DB2 database system also supports full XQuery,SQL/XML, and XML Schema support. Imagine that the system of the presentinvention receives the following query:

“What are the current locations of food that originated in Bangkok,Thailand that, after last Saturday, were within 1 mile of chemicals thatwere in San Pedro, Calif. harbor last Saturday?”

After the relevant data has been collected, data repositories which arekeyed on RFID may be created as shown below:

1. RFID, entity instance of “chemical” . . . 1 record per batch of achemical (Source 1.1)

2. RFID, time, location . . . 1 record per batch of a chemical in aparticular location at a particular time (Source 1.2)

3. RFID, entity name, location=<official address as GPS coordinates>

4. RFID, entity instance of “food” . . . 1 record per instance of a fooditem (Source 2.1)

5. RFID, time, location . . . 1 record per instance of a food item in aparticular location at a particular time (Source 2.2)

Multiple tag data repositories may need to be crawled. The aggregationof this disparate tag data enables the answer to our query. The datarepositories shown above may need to be crawled regularly. Sources 1.2and 2.2 may need to be crawled more frequently than sources 1.1 and 2.1.

After the data repositories have been crawled and the appropriate datastructures have been constructed, processing the query may proceed asfollows:

1. Get the (location, radius) of San Pedro harbor.

2. Get the set of chemicals that had space coordinates within San Pedroharbor in the time interval=[Saturday, midnight; Sunday, midnight].

3. Get the (location, radius) of Bangkok, Thailand.

4. Get the set of RFIDs of food whose origin space coordinates arewithin Bangkok, Thailand AND have any time coordinates (i.e., existed)on or after last Saturday.

5. Get the set of time-space coordinates of food in step 4, such thatthe time coordinate is after last Saturday.

6. Get the set of time-space coordinates of chemicals in step 2, suchthat the time coordinate is after last Saturday.

7. Get the set of (food) time space coordinates from the set of step 5that match a (chemical) space-time coordinate in step 6, where “match”is defined to mean that their time coordinates are within some epsilonand their space coordinates are within 1 mile of each other.

8. Get the set of food associated with the time-space coordinatesretrieved in the previous step.

9. Return the set of last recorded space coordinates of the foodretrieved in the previous step.

A Tag Data Type System

Entities that are tagged generally are related to other tagged entities.Two kinds of associations have emerged as of primary value: is a (read“is a”) relations and has a (read “has a”) relations. An Americancitizen is a human being. A Toyota is a car. A human being has a heart.An American citizen therefore has a heart. An American citizen has aright to keep and bear arms. Since not every human being is an Americancitizen, it is not valid to assert that “If an entity is a human, thenthat entity has a right to keep and bear arms. A car has a steeringwheel. A Toyota therefore has a steering wheel. Type systems where eachentity has a unique is a relationship are called single inheritance typesystems. Such type systems give rise to a type hierarchy, whose roottype is the most abstract entity. For example, in the Java programminglanguage, Object is the root of the class hierarchy. Type systems whereeach entity does not necessarily have a unique is a relationship arecalled multiple inheritance type systems. The type graph of such aninheritance system is a directed acyclic graph. In a multipleinheritance type system, it may be that a square is a rectangle and asquare is a rhombus, inheriting the right-angled property of rectanglesand the equal-sided property of rhombuses.

Tag data clearly can profit from a type system for essentially the samereasons that an object-oriented programming language and/or databaseprofits from a type system. For example, when one is declaring aToyota's tag data, one can declare that a Toyota is a car. Since a carhas a steering wheel, if the Toyota tag data specification does notinclude a steering wheel, it is not conforming to the car tag data“interface”, and thus is in error. Such type-checking catches sucherrors early, and that doing so saves a lot of time and money. Searchingand querying can be enriched with the reserved words is a and has. Forexample, issuing the search

-   -   “is a vehicle AND has a battery AND “Bethesda”

might yield tag data for cars, boats, and other vehicles that have abattery and in some way are associated with Bethesda (e.g., are locatedin Bethesda, Md.). This search uses the fact that is a is transitive.For example, since John Smith's 1999 Toyota Corolla is a Toyota which isa car which is a vehicle, John Smith's 1999 Toyota Corolla is a vehicle.Has a, on the other hand is not transitive. If a car has a passenger andthe passenger has a heart, we would not conclude that a car has a heart.We however could ask if there is an x such that a car has an x and x hasa heart. A shorthand for this might be “car has a has a heart” or morebriefly “car has a² heart.” An extension of this is x has a* y whichmeans there is a chain of has relations that connects x to y.

A Simple Implementation Taxonomy

Different tag data repositories of the present invention may havedifferent authorization requirements. Indeed, the embodiments of thepresent invention may vary according to two dimensions: The set of tagdata repositories and the set of authorized users. We thus subdividethis space into four categories, shown in FIG. 7. Category Iembodiments—few authorized users querying over a few tag datarepositories—may be special-purpose, advanced systems for specializedusers (e.g., a corporate system for an automobile manufacturer).Category II embodiments—many authorized users querying over a few tagdata repositories—may be populated with tag data repositories thatcontain tag data that is either public or privately owned but intendedfor wide dissemination (e.g., a government system of tag data, such asdata associated with the physical manifestation of proposedlegislation). Category III embodiments—few authorized users queryingover many tag data repositories—may be used, for example, by authorizedfederal law enforcement agents. Category IV embodiments many authorizedusers querying over many tag data repositories—might, for example, bebased on the public part of a large number of tag data repositories.Such implementations may be services (e.g., a tag data analog of GOOGLE(Tagoogle)) that are widely subscribed.

While the above invention has been described with reference to certainpreferred embodiments, the scope of the present invention is not limitedto these embodiments. One skilled in the art may find variations ofthese preferred embodiments which, nevertheless, fall within the spiritof the present invention, whose scope is defined by the claims set forthbelow.

What is claimed is:
 1. A method for accessing and organizing tag-relateddata, the method being implemented by at least one computer includingone or more processors and comprising: accessing data associated withone or more tags from one or more data repositories, the one or moretags having one or more tag identifiers, the data associated with theone or more tags including location information of the one or more tags;linking together at least one portion of the accessed data that isassociated with at least one of the one or more tag identifiers, toprovide location information of an object using the location informationof the one or more tags; determining two or more tag identifiers thatsatisfy a query or keyword search; and ranking the determined two ormore tag identifiers based on tag references of the determined two ormore tag identifiers.
 2. The method of claim 1, wherein the dataassociated with the one or more tags is represented with a physicalmarkup language.
 3. The method of claim 1, further comprising:constructing one or more data structures to organize the data associatedwith the one or more tags.
 4. The method of claim 3, wherein the one ormore organized data structures comprise at least one database and atleast one index.
 5. The method of claim 4, wherein the at least oneindex comprises an inverted index.
 6. The method of claim 4, wherein theat least one index comprises a primary index and a secondary index. 7.The method of claim 3, further comprising: storing the accessed dataassociated with the one or more tags in the one or more data structures.8. The method of claim 3 further comprising: populating the one or moredata structures with electronic addresses of the data associated withthe one or more tags.
 9. The method of claim 6, further comprising:responding to the query or keyword search with a list of aggregated dataassociated with the determined two or more tag identifiers.
 10. Themethod of claim 1, further comprising: forming an ordered list ofaggregated data.
 11. The method of claim 1, wherein the steps ofaccessing data, linking data and storing data comprise crawling throughthe one or more repositories.
 12. The method of claim 1, wherein atleast one of the repositories has a first owner and at least another ofthe one or more repositories has a second owner that is different thanthe first owner.
 13. The method of claim 1, wherein the query includes aquery from a parent requesting the identity of people that came intocontact with a child.
 14. The method of claim 1, wherein the accesseddata associated with the one or more tags includes chain of titleinformation and environmental condition information obtained by one ormore sensors.
 15. The method of claim 1, wherein further comprisingperforming proximity tracking of the one or more tags and recording anevent when a tag comes within a range of other tags.
 16. A system forretrieving and organizing data that is associated with one or more tagshaving one or more tag identifiers from a plurality of repositories, thesystem being implemented by at least one computer including onecomprising a processor that: retrieves data associated with one or moretags from one or more of the repositories, the one or more tags havingone or more tag identifiers, and the data associated with one or moretags including location information of the one or more tags; linkstogether at least one portion of the data that is associated with atleast one of the one or more tag identifiers, to provide locationinformation of an object using the location information of the one ormore tags; determines two or more tag identifiers that satisfy a queryor keyword search; and ranks the determined two or more tag identifiersbased on tag references of the determined two or more tag identifiers.17. The system of claim 16, wherein the processor further: responds tothe query or keyword search with a list of aggregated data associatedwith the determined two or more tag identifiers.
 18. The system of claim17, wherein the processor further: receives a selection from the list ofaggregated data.
 19. The system of claim 16, wherein the processorfurther: constructs one or more data structures to organize the dataassociated with at least the one or more tag identifiers.
 20. A methodfor accessing and organizing tag-related data, the method beingimplemented by at least one computer including one or more processorsand comprising: accessing data associated with one or more entities, theentities associated with one or more tags having one or more tagidentifiers, the data being stored in one or more data repositories,wherein a step of accessing data associated with the one or moreentities is triggered by a first event notification; accessing dataassociated with one or more other entities, the other entitiesassociated with one or more tags having one or more tag identifiers, thedata being stored in one or more data repositories, wherein a step ofaccessing data associated with one or more other entities is triggeredby a second event notification; and linking the accessed data associatedwith the one or more entities together with the accessed data associatedwith the one or more other entities using the one or more tagidentifiers; determining two or more tag identifiers that satisfy aquery; and ranking the determined two or more tag identifiers based ontag references of the determined two or more tag identifiers.